-peter olson



Mardi 12, 192.9. p... OLSON y .1,704,836

PNEUMA'TIC DISPATCH TUBE APPARATUS Filed Sept. 14. 1927 \1 8% 6 Nd WSS; 3 Y Wp: g N. Vm N Patente-d Mar. 122, lgl.

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UNITE STATES PATENT OFFlCE.

PETER OLSON, OF OAK PARK, ILLINOES, ASSIGNOR TO SAMUEL OLSON &

COMPANY,

0F CHCAG-O, ILLINOIS, A CORPORATION OF ILLINOIS.

. PNEUMATIC-DISPATCH-TUBE APPARATUS.

Application filed September 14, 1927.

This invention relates to improvements in pneumatic dispatch tube apparatus and particularly to the type in which a minimum flow of air is maintained through the transmission tube when no carriers are in transit, while means is provided for increasing the flow automatically' upon the introduction of the carrier into the transmisif-'on tube. rlhe purpose of the invention is to provide a relatively simple and dependable apparatus tor automatically controlling the flow of air in the transmission tube as needed and it consists of certain features and elements ol construction in combination as herein shown and described and as indicated by the claims.

In the drawings:

Figure 1 is a somewhat diagrammatic View of one complete circuit otl a pneumatic dispatch tube system to which this invention is applicable.

Figure 2 is a vertical section of the valve controlling apparatus taken substantially at the axis of the tube and through the axes of the pneumatic devices which constitute it.

Referring first to Figure 1 there is shown at A a tank or reservoir which may be considered as a source of suction for the purposes of the invention. It may be understood that a suitable air pressure or suction pump will be connected with this reservoir for producing the reduced pressure in the tank, A. A suction supply pipe, B leads from the tank, A, through a valve casing, C, to the connecting pipe, D, which altords communication with the transmisison tube of the system. This consists of two runs ot tubing indicated at E and El, constituting outgoing and returning paths for carriers bctween the two stations, F and G. At the station, F, the tubes, E and El, are connected by a coupling, Il, which is .normally airtight, having a spring door, H1, which is opened temporarily for introduction of a carrier lo be transmitted from lil to (l. .\l stallion, (l, tbe carriers are introduced at the mouthA J, ot the tube, lill, and are discharged past a spring door, K, at the station, F. As thus tar described, the system is typical of hose in common use; my invention relates to the mechanism associated with the valve in the casing, C.

Communication between the suction tube, B, and the connecting tube, D, is controlled principally by a valve, 1, which is normally closed when there are no carriers in transit Serial No. 219,465.

in the tubes, E and El. But at such times a partial or restricted How of air is maintained1 through ports, 2 and .3, formed in the partition wall of the casing, C. A pneumatic device comprising a diaphragm, 4, is arranged adjoining the casing, C, and is in constant communication with the suction tube, B, through an opening, 5, at the center of the pneumatic chamber, 6. A rod, 7, extends through the opening, 5, from the diaphragm, 4. to the valve, 1, to serve as an operative connection from the diaphragm to the valve. The partial vacuum maintained in the tube, B, is normally communicated to both sides of the diaphragm, 4, through a by-pass, 8, with ports, 9 and 10, leading' to the chambers, G and 11, at opposite sides ot' the diaphragm respectively. An atmosphere vent port for the chamber, 11, is controlled by a valve, 12, and it will be apparent that when this valve is opened the atmospheric pressure admitted to the chamber, 11, being greater than the pressure maintained in the chamber, 6, will force the diaphragm, 4, in the direction for opening the valve, 1. This opening of the valve, 1, is desiredwhen a carrier is placed in either line, E, or El, ofthe transmission tube so that full suction may be applied to the carrier for moving it as rapidly as possible from one station to the other. To secure the opening ol the valve, 1, whenever a carrier is placed in the transmisison tube, I provide a second pneumatic device comprising a diaphragm, 14, which separates chambers, 15 and 16, the former being constantly subject to atmos pheric pressure through ports, 17, in its wall. The other chamber, 16, communicates through a tube, 18, with the transmission tubes by way of the connecting pipe, D, into which it leads directly. This places the chamber, 16, under substantially the same pressure which exists in the transn'iission tube and, as previously explained, a partial llow of air is maintained through the transmission tube by way of the ports. '2 and Sl, in the partition of the valve casing, C. Upon introduction ol' a carrier into the transmission lube, this partial or minimum How ot air is temporarily choked and the pull of the suction through the tube, B, produces a higher vacuum in the transmission tubes and connecting tube, D, which reacts in the chamber, 16, to move the diaphragm, 14, in opposition to its spring, 19. The rod, 20, which is rigidly attached to the diaphragm, 14, at

its center, is thus shifted in the direction for encounter of its abutment, 21, with the arm, 22, of a bell cra l( lever, 23, tulcrnrned in a bracket, 2li, which is shown supported on the casing of the iii-st pneumatic deuiee. rfhe lever, 2?), connects through a linl7 25, with a. lever arm. 28, which carries the valve, 12. so that this linkage and the second pneumatic with its diaphragm, 14, constitutes a trip device for admitting atmospheric pressure to one side of the diaphragm, 4, when a carrier is entered in the transmission tube, E, El. As' already explained, this venting of the pneumatic chamber, 11, causes the diaphragm, 4, to torce open the valve, 1, and thus admit to the transmission tube: the full torce of the suction Vfrom the source, A.

,is soon as the valve. 1. is opened the temporarily high vacuum in the passage, D. will be sorueu'hat relieved and the pressure in tube, 18. and chamber. 16, will consequently rise und alloc.'v the diaphrzunn, lll. to more buck to normal position as shown in Figure The exact prevenire condition under Which this will occur will bc determined by the pressure exerted oy the spring. 19, which may be adjusted to the desired amount by the screw. Qi'. The abutment, Q1, is preferably formed by the under side ot the rounded head, Q8, ot the rod. Q0. and one side ot the lever arm, 22, is beveled at Q9 for encounter' with the rounded side ot." the head. as the rod, Q0, returns to normal position. An open slot, 30. in the pivot connection between the link, 25 and lever. 26. and a spring. 31, stretched between the lever. QG, and one arm of the lever, 23, permits the bell crank lever to yield momentarily as thc head ot the rod, 20, passes it. The pneumatic ot' the trip device is thus reset almost immediately after opening of the valve, 1.

The atmosphere vent valve, 12, also returns promptly to its normally closed position under the influence of gravity, though a spring` might be substituted to perform this work. The weicht ot the parts maybe nearly balanced bf; a ,'untern'eigjhh 32, on the lever, QG, so as lo maire them readily operable by the diaphragm. il, but they will be slightly overbalanced in hc direction tor closing the vulve. l2. .is :Icoon as the valve, l2. has closed the suction :u' ing,r through the ily-pass. S. and the pori. itl, begins to reduce the p! efsurc in ilu` chanilcr. ll. and this reduction continues unil the pressures in the chambers. 1l and l, are n equals-thc time required for this ouah/.ation being determined by means of a regulalinpy needle Valve, il?

n whose screwihrcaded ein. 34, is carried in a bushing, 35, screwed into an enlarged opening, 36. in the base ot the pneumatic casingy and concentric with the passage, 8. The adjustment ot' the valve, 33, is maintained by a lock nut, 3T, abuttingthe bushing, 35. The exposed portion of the bushing at 38 may be made nonprocese circular o that by unscrewing the bushing' the f, faire may be removed with the bushing ront disturbing its adjustment therein r to permit cleaning out the oy-pass, 8,

therein should interfere with proper n g ot the mechanism. iis the pressures in chambers, G and l1. approach equalization the compressed spring', lll, reacting' against the val 0, 1, and diaphragm, 4, will torce the valve back to closed position and it the timing,y valve, 33, has been properly adjusted, this will usually occur just as the carrier is discharged at its destination. lf the valve, 1, should close betere the carrier has traveled lo the point oit discharge, the continued presence of the carrier in the transmission tube will again choke the tube so as to produce a momentarily high vacuum which will react again through the connection, 18, and diaphragm, 1li, to trip open the vent valve. l2, and again actuate the diaphragm, Il, V3or (,'peningr the: suction valve, 1. Likewise, 1;" a :-fccoiid carrier is introduced into the transmission tube before the first one has been discharged, the momentarily high vacuum will be again produced immediately upon closing ot the valve, 1, and the valve will be reopened as just described so as to apply full torce to the suction for drawing the second carrier through the transmission tube. In other Words, the vent. valve, 12, will be tripped repeatedly as long as there is any carrier in the tra srnission tube ot the system, although the closing of the valve, 1, may cause the progress ot the carrier to be momentarily retarded.

It will be understood that in a complete system each circuit such as that represented by the tubes, E and E1, will be provided With its Valve-controlling mechanism of the character .shown in Figure 2 so that the timing needle valve, 83, ot each such mechanism may be adjusted to correspond approximately Wit-h the length ot' the particular circuit Which it serres.

l claim 1. A pneumatic dispatch apparatus comprising; a transmission tubo and a source of suction with a normally closed valve interposed between them and a pneumatic for operalinn said valve normally exposed to the suction at both sides; a by-pass associated with y,aid pneumatic to permit eipialization ot jncssurcs at its opposite sides and a regulatingh needle valve in said lay-pass compris- 'nur a pointed screw, an internally and exicriorly threaded bushing set in the casing,r ot the pneumatic and in which the screw is threaded. and a lock nuton the screw abutting the bushing for holding the screw at any adjusted position whereby the screw and bushing may be removed bodily and then re-placed Without disturbing the adjustmentof the screw.

s ports, 9 and 10, it any accumulation ot 2. .ln a pneumatic dispatch apparatus, a control device eomprieing` a pneumatic motor including a easing' having two chambers with a pressure responsive element separating` them, a ley-pasa connecting said chambers for equalization of pressures between them and a regulating;l needle valve in Said by-paes comprising a pointed screw, a buehing in which said screw is threaded for adjustment, a lock nut on the screw abutting 10 the bushing for maintaining adjustment7 the bushing being removably secured to the Casing of the pneumatic motor device to permit bodily removal and replacement of the screw without disturbing its adjustment.

PETER OLSON. 

